The field of this disclosure relates generally to systems and methods for data reading, and more particularly, to checkout station systems incorporating covers or weigh scale platters configured for use with data readers.
There are many types of optical codes that use various symbologies, including one-dimensional barcodes, such as a Universal Product Code (UPC) and EAN/JAN codes; stacked codes, such as PDF417; and two-dimensional codes, such as Maxicode codes. Such optical codes have widespread applications. For example, optical codes can be used to identify a class of items (e.g., merchandise) or unique items (e.g., patents). Thus, optical codes are found on a wide variety of items and objects, such as retail goods, company assets, and documents.
Optical code readers can be configured to acquire data from 1-D, stacked, and 2-D optical codes, as well as other types of optical codes or symbols and images of other items, such as biometric items. Two types of optical code readers used to acquire data associated with an optical code are laser scanners and imager-based optical code readers—the latter are also referred to as imaging readers. Both scanners and imaging readers may be referred to more generally as data readers, or simply, readers. Therefore, for purposes of the present disclosure, the terms scan and read may be used interchangeably to connote acquiring data associated with an optical code. Likewise, the terms scanner and imaging reader may be used interchangeably to connote devices used to acquire data associated with an optical code. Nevertheless, imaging readers actually employ a camera, imaging device, or sensor array, such as a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) device to receive light reflected from an optical code and to thereby generate electronic image data (typically in digital form) representing the optical code. The image data is then processed to locate and decode the optical code.
Optical codes are typically placed on items and read or scanned by data readers to help track item movement in industrial or shipping facilities or to monitor sales and inventory at retail establishments. The optical codes are placed on or associated with items, packages, containers, or other objects to be read by the data reader when the items bearing the optical codes are passed through (i.e., swept past) a read zone during a data-reading operation. For example, in retail stores, data readers are placed at checkstands or are built into a checkstand counter and generally include one or more read volumes (or scan volumes) that combine to collectively establish a read zone in which optical codes may be successfully read. In other words, a read zone means one or more read volumes and the extent of the read zone is typically defined by a field-of-view (FOV) and a depth-of-field (DOF) of one or more associated imaging devices.
Previous attempts to delineate a single scan volume have relied on simple indicators or targets placed directly on scanner windows with adhesives or other bonds. These indicators easily wear off, occlude the scan volume, or simply fall off the scanner over time. Other attempts have indicated a small segment of a read zone using subtle arrows or other rudimentary marks.
Although some imaging readers are capable of using ambient light illumination, imaging readers typically utilize an artificial light source to illuminate an item in the read zone and to thereby provide sufficient signal response (i.e., exposure) for the data reader imaging device. In some instances, the illumination can be a distraction to users.